Duplicating attachment



July 6, 1937. D. NELSON DUPLICATING ATTACHMENT Filed A pril, 1955 5 Sheets-Sheet l TTl gmc/wld@ Lew/.s D. Ne/Jon July 6, 1937. D. NELSON I 2,085,993

DUPLIGATING ATTACHMENT Filed April 4, 1955 :s sheets-Sheet 2 FME-1D- I FTEQ.

July 6, l937l. l.. D. NELSON 2,085,993

DUPLTCATING ATTACHMENT Filed April 4, 1955 5 Sheets-Sheet 5 --.wvl

Patented July 6, 1937 UNITED sTATEs PATENT oFFlCE 2,085,993 DUPLICATING ATTACHMENT Mich.

Application April 4, 1935, Serial No. 14,669

2 Claims. (Cl. 197-153) This invention relates to typewriters, and is particularly directed to a duplicating attachment to produce multiple copies by a single key stroke.

The primary object of the invention is the provision of a simple and eicient duplicating mechanism which may be readily attached to any standard typewriter for the purpose of making copies of the matter written in the machine without the use of carbon paper.

Another object of the invention is the provision of vsimple and efcient mechanism to operate a duplicating ribbon and cause progressive movement thereof in a vertical direction.

Other objects and advantages of the invention will become apparent as the description proceeds,

reference being had to the accompanying drawings in which- Figure 1 is a diagrammatic front elevation, with parts broken away, of a typewriter machine equipped with my duplicating attachment; Fig.

2 is a, diagrammatic side elevation, with parts in section and parts broken away, of the duplieating attachment applied to a machine, with the parts indicated in dotted lines in the position occupied when in inoperative position; Fig. 3 is an enlarged view of the duplicating ribbon tip with its relation to the platen and paper used in a machine; Fig. 4 is a section on the line 4-4 in Fig. 2; Fig. 5 is a section on the line 5-5 in Fig. 6; Fig. 6 is a section on the line 6-6 in Fig. 5, showing a top View of the ribbon operating mechanism; Fig. '7 is an enlarged fragmentary view of a vertical adjustment for the ribbon tip; Fig. 8 is a central vertical section on the line 8 8 in Fig. 6; Fig. 9 is a section on the line 9-9 in Fig.

8 to show one adjusting mechanism for the duplicating head; Fig. 10 is a section on the line III-I0 in Fig. 5; Fig. 11 is a, diagrammatic side elevation of a modified form of frame structure attached to a typewriter frame, and Fig. 12 is a fragmentary front elevation thereof, with parts of the modified frame structure shown in Fig. l1 broken away.

Referring to the drawings, the present invention is shown in connection with a typewriter designated generally by I, having a platen 2 and back frame standards 3 to which my duplicating mechanism is conveniently attached.

The supporting frame for the duplicating mechanism preferably comprises a horizontal cross-piece 4 having an inturned jaw member 5 on each end which is adapted to be clamped into engagement with the rear frame uprights 3 of the typewriter. A vertical supporting member 6 is preferably fixed to the cross-piece 4 centrally thereof, and extends upwardly to a point substantially on a level with the top of the machine. A curved swinging arm 1 is pivoted to the top of the member 6 and carries at its outer end a duplicating head generally designated by 8. The arm 1 is swung back out of the way, whenever paper is placed in the machine or it is desired not to use the attachment. o

The duplicating head4 B, as shown in Figs. 5, 6, and 8, comprises a frame member III, which carries ribbon rolls I2 and I3 on suitably disposed removable shafts I5 journalled in the frame. A ribbon I6 is wound on the rolls I2 and I3 and extends outwardly intermediate the rolls to be trained over a suitable ribbon tip I1, which latter is curved to conform substantially to the curvature of the platen 2. The ribbon tip, which comprises a thin tongue-like strip attached at its inner end to the frame I0, is slotted adjacent its outer end as at I9 and the slot is interrupted by a horizontal cross-piece 20 around which the ribbon I6 is trained so that it may be reversed to run back to the rolls.

The operating mechanism for the ribbon rolls includes a similar gear 22 carried outside the frame I0 on each of the shafts I5. A driving pinion 24 is carried by a shaft 25 journalled between the arms of a U-shaped rocker-frame'26, pivoted to the frame Ill, as at 28, so that it is adapted to swing into engagement with either of the gears 22 in a manner hereinafter described. An actuating pulley 30 is carried by the shaft 25 and is free to rotate thereon. The pulley 30, as shown in Fig. 5, carries a pawl 32, which is adapted to engage a ratchet-wheel 34 iixed to the shaft 25. It will thus be seen that movement of the pulley 30 in a counter-clockwise direction in Fig. 5 will cause the pawl 32 to engage the ratchet wheel 34 and thus rotate the shaft 25 and consequently whichever of the gears 22 which is meshed with the driving pinion 24 at the time.

Rotation of the driving pulley 30 is conveniently caused by a traversing movement of the carriage of the typewriter. As shown in Fig. 4, an actuating cable or cord 36 is attached 'to one end of the machine carriage A. The cable is thence trained over suitable guide pulleys 31 and 38 carried by the stationary supporting member 6, and thence are trained upwardly over other guide pulleys 39, 40, and 4I journalled on the swinging arm 1. Obviously, any suitable disposition of pulleys may be made so long as the cable is trained in such a manner that it does not contact the relatively stationary parts. The cable is then turned one or more times about the drive pulley 30 and extends back to the carriage,

over suitable idler pulleys located similarly to the above mentioned pulleys 31, 38, 39, etc., and its end is attached to the other end of the carriage A to that iirst mentioned. 'Ihe cable 36 is provided ,near one end with a take-up spring 42. It will thus be seen that, as the carriage moves laterally in the usual manner, the cable 36 will have corresponding movement imparted thereto and will rotate the drive pulley 30. The pawl and ratchet 32 and 34 are disposed so that the ribbon I6 is advanced only when the carriage is moved in its operating direction and remains stationary during a reverse movement thereof.

As shown in Figs. 8 and 9, the duplicatinghead 8 is mounted for limited pivotal movements on the swinging arm 1., being journalled on a pin 50 at the free end of the arm. The head is biased in a downward direction in suitable manner, as by a weak compression spring 52 acting between the arm Band a rear portion of the frame l0. The downward movement, however, is limited by a suitable stop screw 54, which is threaded through a bracket 55 carried by an extremity of the arm 8 and abuts against a lug 51 formed on the lower face of the frame I0. This provision is made so that the head may freely shift with the platen when the carriage is raised to bring it into position to print a capital letter, this position being shown in dotted lines in Fig. 8.

A suitable shifting mechanism is provided for the ribbon roll driving mechanism so that the drive pinion 24 may be selectively engaged with either of the operating gears 22. In the form shown, this shifting mechanism comprises an arm 56 fixed to the inner leg of the U-shaped rocker frame 26 and adapted to swing said frame about its pivot 28. The arm 56 is brought out to a convenient position and terminates in a small handle 58. The arm 56 is movable to place the pinion 24 in engagement with either gear 22, or in neutral position, and is yieldingly held in any of such positions by springing engagement with the proper one of a set of three stop pins 60 on the frame I0.

The operating head is preferably enclosed in a casing 62 to protect all of the parts from dust and to enhance the appearance of the structure. The same holds true for the actuating cable 36 and its attendant pulleys, since a casing 64 is provided therefor on the swinging arm 1.

A slight vertical adjustment for the ribbon tongue l1 is provided so that it may be moved slightly with relation to the frame l0. This adjustment preferably takes the form of a slot and -set screw connection, as shown in Figs. '7 and 8.

.screw 68 which is passed through the frame lll and casing 62.

In operation the arm 1 is swung to the dotted line position shown in Fig. 2 and paper is inserted in the machine in the usual manner. The device is adapted to be used in connection with three sheets of paper, a, b, and c, as shown in Figs. 2 and 3. When so used, two of the copies made will be originals due to the fact that they are directly ink-printed by a blow from a typewriter type, and the other or middle, sheet b, will be back printed. 'I'hus the duplicating head 8 will be placed between the second and third of the sheets with the opening of the tip or in close relation to the platen and in the path of movement of the typewriter type, so that as a type strikes the paper the typewriter ribbon will cause printing on the rst sheet, a, and the Y ribbon I6 will cause printing on the back of the second sheet, b, and the front of the third, c. It will be seen that in this way three copies of the written material will be obtained without the use of any .carbon paper or other duplicating material. 'Ihe ribbon I1 is caused to progress and present a new surface with each movement of the carriage. As the carriage moves. the cable 36 is drawn to a new position, and thus moves the actuating pulley 30 and consequently one ofthe ribbonrolls. Obviously, the movement of the ribbon l1 is in an approximately vertical direction or at right angles to the movement of the ordinary typewriterribbon. When the ribbon I1 is completely unwound from one of the ribbon rolls, a reversal of the drive may take structions to the path of the paper be removed,

the frame consists of similar lateral hollow arms 10 extending from the'back frame of the machine a suicient distance sideways so as to allow the carriage to run its full travel without interference. The frame then extends upwardly and across in a horizontal hollow back frame 12 to which the duplicating head is swingably mounted by a hollow arm 14. The operating cable 36 is trained over suitable pulleys within the hollow arms 10, 12, and 14. It will be understood that the duplicating head 8 is the same in this mechanism as in the previously described form.

While theinvention has been disclosed and described with reference to a specific drive means and operating devices, it should be expressly understood that numerous modifications and changes may be made in the form and disposition of the parts without departing from the invention as defined in the appended claims.

What I claim is:

1. In combination with a typewriter having a laterally movable carriage and a platen, a duplicating head, means carried by the head to project a ribbon in close relation to said platen, a pair of ribbon rolls carried by the head, gears adapted to rotate said rolls, an arm mounted for predetermined swinging movements in said head, a pinion carried by said arm and adapted to mesh with either of said gears and means actuated by a lateral movement of the carriage to rotate said pinion and move said ribbon rolls whereby a new ribbon surface is presented to the platen with each movement of the carriage.

2. In combination with a typewriter having a laterally movable carriage and platen, a duplicating head, means carried by the head to project a 'ribbon in close relation to said platen, a pair of ribbon rolls carried by the head, gears adapted to rotate said rolls, a pinion adapted to mesh with either of said gears, means to move said pinion selectively into engagement with either of said gears and means actuated by a lateral movement of the carriage to rotate said pinion and move said ribbon rolls whereby a new ribbon surface is presented to the platen with each movement of the carriage.

- LEWIS D. NELSON. 

